## Say Hello to 20!

Oh yes! You score 20 out of 20 in a unit test. Wow! That feeling is amazing. Isn’t it? But do you know what 20 is? Well, 20 is a natural number. It is written as ‘twenty’ in numbers. Can you recall where you heard the number 20? 20-20 cricket matches or especially when your mother yelled at you….. “I told you twenty times that don't do this, you moron.” Hey, do not laugh!

In this article, you will learn what is 20 and some interesting facts related to 20.

**What does 20 mean in Maths**

## What is Number 20?

20 is a cardinal number. The number 20 is the successor of 19 and the predecessor of 21. It is an even number. This natural number is written as XX in the Roman numeral. Number 20 is formed from the word of Old English ‘twentig’, from the base of two + -ty.

Number 20 can be written as the following in place value chart:

## Number ‘20’ in Mathematics

Factors of 20 are 1, 2, 4, 5, 10, and 20 because 20 can be written as:

20 = 1 x 20

20 = 2 x 10

20 = 4 x 5

Number 20 is a pronic number as it is the multiplication of two consecutive numbers, i.e., 4 and 5.

20 = 4 x 5

Number 20 is the sum of four consecutive even numbers, i.e.,

20 = 2 + 4 + 6 + 8

In Geometry, the figure which has 20 sides is called an icosagon or 20-gon. Also, an icosahedron has 20 faces and a dodecahedron has 20 vertices.

20 is the sum of three Fibonacci numbers, i.e., 20 = 13 + 5 + 2. Fibonacci numbers are extracted from the Fibonacci series which are formed by adding two previous numbers, which usually started from 0 and 1.

Like the decimal number system based on 10, the vigesimal or base-20 number system is based on 20.

8 p.m. is written as 20:00 hours in the 24-hour clock system.

### Do You Know?

20 is the atomic number of calcium (Ca).

‘Twenties’ is used to show the period of a person’s life from age 20 to 29. It is also used to represent the 20th century.

Number 20 is used as an index in measuring visual acuity in some countries, just like the 6/6 index. (Can you tell which index is used in your country?)

India won the first Twenty 20 World Cup. Let’s cheer!

## Complete the Following Patterns

1. 10 + …… = 20

2. …… + 7 = 20

3. …… - 5 = 20

4. 30 - …… = 20

5. 5 x …… = 20

6. 40 ÷ …… = 20

Answers:

1. 10

2. 13

3. 25

4. 10

5. 4

6. 2

## Conclusion

We hope that this article helped you to understand the number ‘20’. Understanding the concept of the number ‘20’ will be helpful for the kids as it will help them to solve the complex Maths calculations. To know more about other numbers and Mathematical concepts, explore our website.

## FAQs on What does 20 Mean in Maths?

1. Why is the number ‘20’ so special?

Number 20 is very special in Mathematical numbers. It is an even number and has 5 factors. Number 20 is a pronic number and a sum of two tens. Like a binary number system based on 2 and a decimal number system based on 10, there is also a number system based on 20 called as the vigesimal or base-20 number system.

2. How can I teach ‘what is 20’ to kids?

There is no scientific method to introduce the meaning of any number. You can only introduce any number by adding the habit of counting, like 1, 2, 3, …and so on. You can also give your child twenty objects and ask a simple question of how many objects you have? Also, show them the calendars or any other place where the number 20 is written.